package com.xindaoapp.happypet.view;

/*
 * Copyright (c) 2012 Wireless Designs, LLC
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
import android.content.Context;
import android.graphics.Point;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;

/**
 * PagerContainer: A layout that displays a ViewPager with its children that are outside
 * the typical pager bounds.
 */
public class PagerContainer extends FrameLayout implements ViewPager.OnPageChangeListener {

	private ViewPager mPager;
	boolean mNeedsRedraw = false;

	public PagerContainer(Context context) {
		super(context);
		init();
	}

	public PagerContainer(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		init();
	}

	private void init() {
		// Disable clipping of children so non-selected pages are visible
		setClipChildren(false);

		// Child clipping doesn't work with hardware acceleration in Android
		// 3.x/4.x
		// You need to set this value here if using hardware acceleration in an
		// application targeted at these releases.
		setLayerType(View.LAYER_TYPE_SOFTWARE, null);
	}

	@Override
	protected void onFinishInflate() {
		try {
			mPager = (ViewPager) getChildAt(0);
			mPager.setOnPageChangeListener(this);
		} catch (Exception e) {
			throw new IllegalStateException("The root child of PagerContainer must be a ViewPager");
		}
	}

	public ViewPager getViewPager() {
		return mPager;
	}

	private final Point mCenter = new Point();
	private final Point mInitialTouch = new Point();

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		mCenter.x = w / 2;
		mCenter.y = h / 2;
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev) {
		// We capture any touches not already handled by the ViewPager
		// to implement scrolling from a touch outside the pager bounds.
		switch (ev.getAction()) {
		case MotionEvent.ACTION_DOWN:
			mInitialTouch.x = (int) ev.getX();
			mInitialTouch.y = (int) ev.getY();
		default:
			ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y - mInitialTouch.y);
			break;
		}

		return mPager.dispatchTouchEvent(ev);
	}

	@Override
	public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
		// Force the container to redraw on scrolling.
		// Without this the outer pages render initially and then stay static
		if (mNeedsRedraw)
			invalidate();
	}

	@Override
	public void onPageSelected(int position) {
	}

	@Override
	public void onPageScrollStateChanged(int state) {
		mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
	}
}
